Thermoelectric cooler and warmer for food with table top tray

ABSTRACT

A container useful for keeping food or beverages warm or cold includes a combination lid and tray door assembly. The lid and tray are both coupled to the container and to each other. The tray may be pivoted independently of the lid into a table top position and it may be separated from the container and used as a separate tray. The tray and lid are also pivotable together as an integral door assembly, and the lid is pivotable independently of the tray when the tray is removed or deployed as a table top. The overall height of the container is less than the overall length and the overall width so that the container has a low, stable center of gravity which permits it to be used on an unstable surface, such as an automobile seat, and so that the container does not obstruct movement or view of occupants of an automobile when it is used in an automobile. A handle of the container includes a holder for wrapping a power cord thereon, and, when disposed in a downward stowed position, provides a clearance between the bottom of the door and a supporting surface when the container is turned on its side to be used as a front opening cooler or warmer. The thermoelectric engine of the cooler/warmer is constructed as an integral cassette which can be installed or removed from the main body of the container in one piece. Finally, a finned heat sink used in the thermoelectric engine in conjunction with a centrifugal fan is formed as an oblique parallelogram to produce uniform air flow velocity across the width of the heat sink.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improved container, which can beselectively used as a cooler or warmer for food and beverages. Moreparticularly, the present invention relates to a portable containerhaving one or more characteristics that adapt it for use in a motorvehicle and/or dorm room, facilitate its assembly and repair, and/orfacilitate its efficient operation.

2. Description of the Related Art

Coolers are typically in the form of an insulated container which haswalls upstanding from a base to define a top opening to which aremovable cover is mounted. Thus, such coolers are typically rectangularwith two sidewalls and two end walls, and have a pivotal handle assemblymounted to each end wall for carrying the cooler. As such, conventionalcoolers are intended to be disposed solely on the bottom or back wall,and the lid, whether or not hinged along one edge, is simply interlockedwith the container by a friction fit and/or by engagement with pivotallymounted locking carrying handles which selectively engage and hold thelid on the container.

Typically coolers of the type described above are used as ice chests.Thus, when the food and/or beverages are to be kept cool, they areplaced in the container and ice is added to the container to keep thefood cool. Such ice chests have a number of disadvantages. For example,as the ice melts, water will be present in the base of the container andmust be periodically removed. Often, outlet ports are provided in suchcoolers to allow the melted ice to be drained. Still, for the most part,only hermetically sealed containers can be placed within the containerif water damage is to be avoided. Further, to keep the contents cool foran extended period, ice must be repeatedly added.

Furthermore, because ice is required to keep the food and beveragescool, only a relatively small amount of food can actually be storedwithin a cooler of a given size and the weight of the cooler issignificantly increased by the presence of the ice.

It has been proposed to incorporate within a cooler type container acooling system so that when the container is coupled to a power source,food and beverages within the cooler will be automatically cooled. Withsuch automatic cooling, there is no need for ice, and thus the containercan hold more food and beverages than conventional ice chests ofcomparable size. The thermoelectric technology which allows a coolingsystem to be incorporated in a cooler was, to a significant extent,developed by NASA and eliminates the need for bulky compressors andpiping. Furthermore, as an alternative to cooling, such newly developedsystems can be used to warm foods by reversing the polarity of the powerto the system. Because such alternative cooling/heating systems areknown a detailed disclosure of the heating/cooling system is omittedherein.

With the advent of positive cooling or warming within a portablecontainer, there has been a desire to provide a portable food containerwhich can be used both in a conventional ice chest orientation with thelid or door on top and in an end up orientation as a "college dormroom", hotel, or office refrigerator/warming oven with a front openingdoor. A structure of this type is described in U.S. Pat. No. 5,319,937,the disclosure of which is hereby incorporated by reference.

While portable cooling/warming containers, such as that described in theaforementioned '937 patent, have a number of advantages, that is not tosay the improvement thereof is not possible. For example, when a cooleror warmer is used as a top opening ice chest, the cooler itself providesno tray or table top structure other than the top of the top openinglid. Obviously, it is not possible to open the lid while food,beverages, or other items are setting thereupon without displacing theitems. Furthermore, when such a thermoelectric unit is used in a motorvehicle, it typically presents an inconvenient and sometimes dangerousinterference with passengers or the driver because of the height of theunit and is subject to tipping because of the high center of gravitythereof. In addition, thermoelectric cooler/warmers adapted for use inmotor vehicles will typically have a long power cord so that thecooler/warmer may be used in the back seat of a car or in the back of avan while plugged into a cigarette lighter receptacle in the dashboardof the vehicle. It is desirable to have a means for stowing the cordwhen not in use or stowing excess cord when less than the whole lengthof cord is needed. One proposal includes cleats for wrapping the cordthereon located within a recess on a lower rear portion of thecontainer. The cleats are not easily accessible and, because they arebuilt within a recess formed on the main body of the container,introduce manufacturing complexities that raise manufacturing costs.

Another problem encountered with thermoelectric cooling/warming units isthat the components of the thermoelectric unit (often known collectivelyas the "thermoelectric engine") are built into portions of the bodyand/or lid of the cooling/warming unit. Therefore, insertion, removal,and repair of the thermoelectric components comprising thethermoelectric engine can be difficult from a manufacturing andmaintenance standpoint. Finally, it is always desirable to maximize theefficiency of a thermoelectric engine, such as that used in acooling/warming unit.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a thermoelectriccooler/warmer which overcomes the shortcomings of conventionalthermoelectric units set forth above.

This object is achieved by providing a container having a main body anda door assembly which includes a tray and a lid which separably engageone another and the main body of the container. The tray is engaged withthe container in such a way that (1) it can be pivoted 180° so as to bemovable between a stowed position in which it engages the lid and adeployed position so as to be usable as a fixed table top surface, (2)the lid can be opened independently of the tray so that it can be openedwhen the tray is deployed as a table top surface, or (3) the tray canremain engaged with the lid while the lid is opened from the container.The tray is removably attached to the lid so that it can be removed fromthe lid and used at a location distant from the container, such as onthe lap of an automobile occupant to hold food and beverage or to writethereon.

This object is also achieved by providing a container having a lowheight relative to the length and width of the container so that it canbe disposed on the seat of a car and remain thereat without obstructingthe movement or view of the occupants of the car and so that it can beconveniently used, e.g., taking advantage of the tray and lid featuresdescribed above.

This object is also achieved by providing the container with a handlethat includes a cord stowing holder so that an electrical cord can beconveniently wrapped around the holder. Because the holder is located onthe handle, it is easily accessible and easily manufacutered.

This object is also achieved by providing a container having a handleand at least one projecting rib on the side of the box designed so that,with the handle in a downward stowed position, the container can be seton its side, resting in a level, stabilized position on a portion of thehandle and on the side rib, and used as a front-opening refrigerator orwarmer. The clearance between the bottom edge of the front-opening doorand the supporting surface afforded by the handle and rib permit thedoor to swing open and closed without scraping the supporting surface.

This object is also achieved by providing a thermoelectric engine andhousing designed as a "cassette" which can be easily inserted andremoved from the container as a single unit by means of several screwsor other suitable attachment means. This facilitates assembly, repair,and/or replacement of the thermoelectric engine with a minimum amount oflabor and without unnecessary replacement of other parts of thecontainer.

It is another object of the present invention to improve the efficiencyof a thermoelectric unit, such as the type used in a cooler/warmercontainer. This object is achieved by providing in the thermoelectricengine a finned heat sink having an intake end shaped to facilitate moreefficient and uniform movement of air through the heat sink, thusimproving the efficiency of heat transfer from the heat sink body to theair flow.

These and other objects, features, and characteristics of the presentinvention as well as the methods of operation and functions of therelated elements of structure, and the combination of parts andeconomies of manufacture, will become more apparent upon considerationof the following description and the appended claims with reference tothe accompanying drawings, all of which form a part of thisspecification, wherein like reference numerals designate correspondingparts in the various figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the heater/warmer of the presentinvention with the handle shown upright in an operative carryingposition;

FIG. 2 is a top plan view of the heater/warmer of the present inventionwith the handle in a downward stowed position;

FIG. 3 is a front elevation of the cooler/warmer of the presentinvention with the handle in the stowed position;

FIG. 4 is an exploded perspective view of the cooler/warmer of thepresent invention showing the lid structure and the tray structuredetached from the main body of the unit;

FIG. 5 is an exploded perspective view from an opposite direction asshown in FIG. 4;

FIG. 6 is a perspective view of the cooler/warmer with the tray deployedin a table top position;

FIG. 7 is a perspective view of the cooler/warmer with the traystructure attached to the lid structure and with the lid pivoted into anopened position;

FIG. 8 is a perspective view of the cooler/warmer with the tray deployedin the table top position and the lid structure pivoted into an openposition independently of the tray;

FIG. 9 is a perspective view of the cooler/warmer situated in afront-opening orientation with the tray structure attached to the lidstructure and with the lid pivoted into an opened position;

FIG. 10 is an exploded perspective view of the cooler/warmer withouteither the tray or lid structures and showing assembly of the unit witha thermoelectric engine and a thermoelectric engine cover;

FIG. 11 is an exploded perspective view of a thermoelectric engine;

FIGS. 12A and 12B are the bottom and top, respectively, of an outerplate of the thermoelectric engine cassette;

FIGS. 12C and 12D are the bottom and top, respectively, of an innerplate of the thermoelectric engine cassette;

FIG. 13 is a plan view of a finned heat sink formed as an obliqueparallelogram according to the present invention; and

FIGS. 14A-14D illustrate air flow from a centrifugal fan and scrollhousing into four different heat sink configurations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A portable cooler/warmer according to the present invention is generallydesignated by reference number 20 in FIG. 1. As shown in FIGS. 1-10 thecooler/warmer 20 includes a main body 22 which comprises four sidewalls24, 26, 44 and 46 extending upwardly from a base wall 60 (see e.g.,FIGS. 4 and 5). Base wall 60 and sidewalls, 24, 26, 44, and 46 definecompartment 62. Front and back sidewalls 24 and 46 each include aplurality of ribs 48 while end walls 26 and 44 are preferably, but notnecessarily, devoid of rib structures. It will be appreciated thatdesignation of a sidewall as either a front, back, or end wall is purelyfor purposes of convenience in the description of the main body 22.

The side and base walls of the main body 22 are preferably formed of amolded plastic material, such as polypropylene. In addition, thesidewalls and base wall are preferably insulated in a conventionalmanner.

The top of the cooler/warmer is comprised of a thermoelectric unit cover50 which covers a thermoelectric unit, preferably a thermoelectricengine, to be described in more detail below. The top of thecooler/warmer further includes a door assembly 52 comprised of a lid 54and tray 56 (see FIGS. 4 and 5). As shown in FIGS. 1, 3 and 7, the lid54 and the tray 56 are detachably connected to each other so as to formthe aforementioned integral door assembly 52. As shown, for example, inFIGS. 6 and 8, the underside of tray 56 is preferably provided with aplurality of tabs 106 proximate each of the four corners thereof. Tabs106 on tray 56 engage receiving slots 80 formed proximate the fourcorners of the lid 54 as shown in FIGS. 4 and 5. Depending on therelative sizes of tabs 106 and slots 80 and also on manufacturingtolerances and wear of the respective parts, the engagement of each tab106 with each slot 80 may vary between a frictional fit, a press fit, ora snap fit. Also, it will be appreciated that the tab and slotarrangement just described could be reversed. That is, tabs could beprovided on the lid 54 which engage corresponding slots formed on thetray 56. Alternatively, tray 56 and lid 54 could be coupled to oneanother by other means, such as protuberances, or other protrusions,formed on either the tray or lid which engage, e.g., snap into,corresponding openings formed in the other.

Tray 56 and lid 54 are preferably formed of a molded plastic material,such as polypropylene, and it can be appreciated from FIGS. 1, 3 and 7that the tray 56 and lid 54 are preferably formed with rounded edges sothat when the two are coupled together to form the integral doorassembly 52 they present a smooth, rounded, aesthetically pleasingstructure. In addition, lid 54 is preferably insulated in a conventionalmanner.

As shown in FIGS. 6 and 8, in accordance with the present invention,tray 56 is constructed and arranged so as to be pivotable with respectto the main body 22 independently from the lid 54. In the illustratedembodiment, this is preferably accomplished by providing two u-shapedhinges 86 (see FIGS. 4 and 7) which engage short lateral posts 90 thatextend laterally from opposite ends of rectangular depressions 88 formedin an edge of the thermoelectric unit cover 50. The respective widths ofthe hinges 86 are preferably slightly smaller than the respective widthsof the depressions 88. As can be appreciated, for example, from FIG. 6,with the hinges 86 seated on the posts 90, tray 56 is pivotable aboutthe four colinear posts 90. It will be further appreciated that,alternatively, the same functionality could be achieved by providing,instead of truncated posts 90, a single rod extending across the entirerespective width of each depression 88. Moreover, the functionalitycould also be achieved by interchanging the post and hinge structures;that is, by providing a suitable hinge structure on the thermoelectricunit cover 50 and corresponding post structure to be engaged by thehinge structure on the edge of the tray 56.

Hinges 86 may comprise clip structures that snap onto posts 90, ifdesired.

To pivot the tray 56 from the stowed position shown, for example, inFIGS. 1 and 3 to a deployed position shown, for example, in FIG. 6, tray56 must be separated from lid 54. Accordingly, it is necessary toovercome the resistance of whatever structure is provided to hold tray56 to lid 54, in the preferred case, tabs 106 on tray 56 which engageslots 80 on lid 54. To assist in gripping tray 56 when separating itfrom lid 54, a gripping indent 104 (see FIG. 5) is provided on an edgeof the tray 56 opposite the hinges 86.

As shown in FIGS. 1 and 2, with tray 56 attached to lid 54 in the stowedposition and with the door assembly 52 closed, tray 56 presents asupporting surface 58 which can be used as a table top to hold food orbeverages, for example, on a picnic or in an automobile. The top surfaceof tray 56 is provided with two raised sides 92 and a raised end 94.Moreover, as can be appreciated from FIG. 3, tray 56, when in the stowedposition, is preferably disposed somewhat below the top ofthermoelectric unit cover 50. Accordingly, the edge of thermoelectricunit cover 50 and raised sides 92 and raised end 94 provide a raisedperiphery around first supporting surface 58 so as to prevent itemssetting thereupon from sliding off of the surface 58.

As shown in FIGS. 6 and 8, when tray 56 is pivoted into the deployedposition, it presents a second supporting surface 66 which is alsouseful as a tray or a table top for setting food, beverages and otheritems thereupon, for example, in an automobile or on a picnic. As can beappreciated from FIGS. 6 and 8, when tray 56 is in the deployedposition, it rests upon and is supported by thermoelectric unit cover50.

With tray 56 deployed as a table top so as to present second supportingsurface 66, the side edges 98 and the end edge 102 of tray 56 extendabove second supporting surface 66 so as to present raised peripheraledges to prevent items set upon second supporting surface 66 fromsliding off of the surface. In addition, raised portion 94 on the top oftray 56 presents a trough 100 on the bottom side of tray 56, which isuseful for holding small items.

It can be appreciated that tray 56 can also be completely removed fromthe container 20 to be used as an independent tray by lifting itstraight off lid 54 (see FIGS. 4 and 5).

While tray 56 is preferably a relatively thin, uninsulated member, itcan be appreciated from FIGS. 4, 5 and 8 that lid 54 is a thickermember, preferably insulated in a conventional manner. Lid 54 isattached to the top of a sidewall of the main body 22 at one end thereofby a hinge assembly that includes engagement structure on the lid 54which engages corresponding engagement structure on the main body. Inthe illustrated embodiment, the hinge assembly includes two cutout areas70 formed in one end of the lid 54 with short circular protrusions, orposts, 72 extending from an outside edge of the cutout areas 70.Although only one post 72 is shown in FIG. 5, it will be appreciatedthat a second post is provided on the opposite cutout area 70 which iscolinear with the post 72 shown in FIG. 5.

Two raised semi-cylindrical members 74, preferably having a width onlyslightly smaller than that of the cutout areas 70, are provided on thetop edge of end wall 44. An outwardly facing circular opening 76 isformed on the outside end of each raised member 74. Openings 76 receivethe posts 72 extending into the cutout areas 70, and it can beappreciated that lid 54 is pivotably coupled with the main body 22 byfitting posts 72 into openings 76. Accordingly, as shown in FIGS. 7 and8, lid 54 is pivotable with respect to the main body 22 of the container20 about the aligned posts 72.

The engagement of posts 72 with openings 76 is preferably a factoryinstalled press fit not intended to be detachable by the final consumer.Alternatively, however, the engagement of posts 72 with openings 76could also be a detatchable frictional fit or a snap fit. In addition,it will be appreciated that, in accordance with the broadest aspects ofthe present invention, a hinge coupling could be achieved by othermeans, such as providing pivoting posts and corresponding receivingopenings on both sides of the cutout portions 70 and raised members 74,respectively, or by interchanging the posts and receiving openings, thatis by providing receiving openings on one or both sides of each cutoutportion 70 and corresponding posts on one or both sides of each raisedmember 74.

As shown in FIG. 7, lid 54 is coupled to the remainder of main body 22at the end opposite the hinge assembly by means of a detent indentation82 formed in an edge of the lid 54, which engages a detent protrusion 84formed in an edge of the thermoelectric unit cover 50. It will beappreciated that the positions of the indentation 82 and protrusion 84could be reversed. Accordingly, lid 54 is secured to the main body 22 ofthe container 20 by both the hinge assembly and the detent structures 82and 84.

As shown in FIG. 6, with lid 54 closed and tray 56 removed or deployedas an independent table top, a supporting surface 68 is presented on topof lid 54.

Lid gripping indentations 78 are preferably formed on either side of thelid 54 towards an end of the lid opposite the hinge assembly tofacilitate gripping of the lid 54 for opening the lid and overcoming thefrictional engagement of the detent protrusion 84 in the detentindentation 82. In addition, it can be appreciated from FIG. 7 that ifclip hinges are employed to couple tray 56 with main body 22, then whenthe tray 56 is stowed onto the lid 54, the door assembly 52 is heldclosed by both the detent structures 82 and 84 and the clip hingesengaged with the hinge posts 90.

As can be appreciated from FIGS. 6-8, the lid 54 and tray 56 can beopened as a single integral door assembly 52, or the lid 54 can beopened independently of the tray 56 when the tray 56 is deployed as atable top.

As shown in FIG. 8, the bottom side of lid 54 is preferably providedwith a peripheral groove 84 for containing a suitable gasket therein.Such a gasket provides an improved seal between lid 54 and the top edgesof the sidewalls of the main body 22 to effectively seal off compartment62. Also, thermoelectric unit cover 50 includes shelf portion 184 whichforms part of the seat for lid 54.

The above-described lid and tray features are shown in the figures asused with a device having positive cooling and warming capability, thatis, a device having a thermoelectric engine. It can be appreciated,however, that in accordance with the broadest aspects of the presentinvention, the advantages of the above described lid and tray can beachieved with a conventional insulated cooler, or other container,having no thermoelectric unit or other electromechanical means ofcooling.

In conventional coolers, the overall height of the unit is typically thesame as or greater than the overall width and the same as or greaterthan the overall length. Accordingly, a conventional unit will have aheight-to-width aspect ratio and a height-to-length aspect ratio ofequal to or greater than 1. This presents a number of disadvantages.First, if the unit is too high, and is used on the seat of a motorvehicle, the unit itself can present an obstacle to the occupants of thevehicle. In addition, a unit with an aspect ratio of greater than orequal to 1 presents a relatively high center of gravity, especially inunits provided with a thermoelectric engine, which is typically providednear the top of the cooler. Accordingly, such a unit can be unstable,especially when used on an inherently unstable surface, such as avehicle seat in a moving vehicle.

As illustrated in FIGS. 1-3, the height of the container 20 of thepresent invention, when used in a top opening ice chest orientation, isless than both the width of the unit and the length of the unit.Accordingly, the container 20 has a height-to-width aspect ratio and aheight-to-length aspect ratio of less than 1. Thus, the unit is lesslikely to present an obstacle to vehicle occupants when the unit is usedon a vehicle seat, and the unit is more stable.

Although not intended to be limiting, it is presently contemplated thata container built according to the present invention would have anoverall height of approximately 11.25", a length of 19", and a width of13.5". On the other hand, a cooler/warmer having a thermoelectric unitthat is available on the market today has a height of about 161/2", awidth of 91/2", and a length of 125/8".

As shown in FIG. 1, the cooler/warmer 20 of the present inventionpreferably includes a u-shaped bail type handle 28 extending across thelength of the unit. The handle 28 includes two leg portions 41 connectedby a transverse portion 43, and the ends 42 of the legs 41 of theu-shaped handle are pivotably coupled to the main body 22 at the centersof opposing end walls 26 and 44.

The preferred structure of the handle 28 includes two coextendingportions 36 and 38 extending substantially parallel to one another forthe entire extent of the handle 28. Coextensive portions 36 and 38 areconnected by a plurality of cross ribs 40 extending therebetween. Such aconstruction presents a strong yet lightweight handle structure.

Cooler/warmer units provided with a thermoelectric warming and coolingability require a power cord so that the thermoelectric engine can beconnected to a power source, such as a wall outlet or a cigarettelighter receptacle in an automobile. Such power cords, especially thoseused in automobiles where it may be desirable to use the cooler/warmerunit in the back seat of a car or in the back of a van, can reachsubstantial lengths of 8 feet or more. Accordingly, it is desirable tohave the ability to conveniently stow the excess cord when not in use soas to avoid entanglement. Therefore, in accordance with one aspect ofthe present invention, a cord holder 30 is provided for wrapping excesscord thereon. Cord holder 30 is preferably attached to the leg 41 of thehandle 28 and includes a longitudinal portion 32 spaced from andconnected to the handle 28 by means of two transverse rib members 34.Cord holder 30 is preferably integrally molded with the handle 28.

In addition to using a portable cooler/warmer unit as a top openingchest, it is often desirable to use the unit as a front opening officeor dorm room sized cooler or warmer. The present invention accommodatesthis flexibility by providing clearance structure on at least one sideof the main body 22 so that the unit may be set upon that side and thedoor assembly can be easily swung open without scraping the surface uponwhich the unit is supported. As shown in FIG. 9 and as can beappreciated from FIGS. 1, 2 and 4, in accordance with the presentinvention, such clearance structure is provided by the ribs 48 formed onthe back side 46 of the main body 22 and the transverse portion 43 ofhandle 28 which extends outwardly from the side of the main body 22 whenit is in its lower stowed position. As shown in FIG. 1, a recess 182 ispreferably provided along the entire length of the back side 46 andalong half the length of the ends 26 and 44. Recess 182 provides aconvenient unobtrusive location in which the handle may be stowed. Ascan be appreciated from FIGS. 2 and 9, the depth of the recess 182 andthe thickness of handle 28 are preferably such that, with handle 28 inthe stowed position, a portion of handle 28 extends outwardly from theside 46 so as to provide clearance structure. Accordingly, it can beappreciated that with the unit 20 tipped onto its back side 46, the unitwill be supported in a stable position upon the transverse portion 43 ofhandle 28 and upon ribs 48.

As shown in the various figures, in the presently preferred embodimentof the invention, ribs 48 are provided toward the lower portions offront and back walls 24 and 46. In the broadest aspects of the presentinvention, however, it is equally contemplated that such ribs could beprovided toward the lower and upper portions of the front and back walls24 and 46 so that the previously described clearance structure isprovided entirely by such sidewall ribs.

A further aspect of the present invention is shown in FIGS. 10 and 11.According to the present invention, a thermoelectric unit, orthermoelectric engine 108, is assembled as an integral modular"cassette" which can be easily installed or removed from the remainderof the cooler/warmer unit 20. Thermoelectric unit 108 is preferablyattached to the cooler/warmer unit by means of screws or other suitablefasteners. In a preferred embodiment of the present invention, aplurality of attachment holes 106 is provided in the top of the sidewalls for attachment of the thermoelectric unit 108 thereto.Thermoelectric unit 108 also includes a plurality of fastening holes 170(see FIGS. 10, 12A, and 12B). In addition, recessed portions 112 and 116are provided across the tops and the upper edges of the inner sides ofthe front, back, and end sidewalls. Recessed areas 112 and 114 furtheraccommodate installation of the thermoelectric unit 108 into thecooler/warmer main body 22.

The thermoelectric unit 108 may include a plug 110 to which a power cord(not shown) may be attached. On the other hand, the power cord could behard wired into the thermoelectric engine, or the thermoelectric enginemay have a portable power source such as a battery pack.

The thermoelectric unit cover 50 is placed over the thermoelectric unit108 when the thermoelectric unit 108 is installed. Thermoelectric unitcover 50 is also preferably held in place by screws or other suitablefasteners. The thermoelectric unit 108 includes one or more fans as willbe described in more detail below. Accordingly, thermoelectric unit 50includes air vents 178 through which air may be moved into or out of thethermoelectric unit cover.

Assembly of the thermoelectric engine cassette 108 will be described inconjunction with FIG. 11.

For purposes of description, the thermoelectric engine cassette 108 isdivided into an inner half for that portion considered to be disposedwithin the cooling/warming compartment 62 of the main body 22 and anouter half for that portion of the cassette considered to be disposedoutside of the cooling/warming compartment 62. An insulating panel 126divides the inner half from the outer half. Insulating panel 126 ispreferably insulated and includes a number of openings and otherformations for accommodating various components of the thermoelectricunit cassette.

Disposed within a rectangular opening 154 of the insulating panel 126 isa thermoelectric module 138. The construction and operation ofthermoelectric modules are well known and thus will not be described inany detail herein. Thermoelectric module 138 is disposed in a moduleretaining device 140, which preferably comprises a square or rectangularframe of approximately the same size as the module 138. A spacer means144, preferably composed of aluminum, is disposed in thermal contactwith the thermoelectric module 138.

Disposed on the outer half of the insulating panel 126 is an outer plate124 and an outer heat sink 122. Also disposed on the outer half is a fanmotor 132 and a centrifugal outer fan 134 operatively coupled with fanmotor 132. A fan motor accommodating cup 164 is provided in the outerplate 124, and the cup 164 is in turn accommodated by a cup 152 disposedin insulating panel 126. An outer fan cover 120 covers both the outerfan 134 and the outer heat sink 122 so as to create a scroll housing 121around the fan and an air plenum 123 around the heat sink.

Details of the construction of the outer plate 124 are shown in FIGS.12A and 12B. As shown in FIGS. 12A and 12B, outer plate 124 includes anopening 158 to accommodate the outer heat sink 122, and the motoraccommodating cup, or receptacle, 164 extends below the upwardly facingsurface of outer plate 124. A slot 161 may be provided on one end of theouter plate for inserting the plug therein. If the power cord is hardwired to the thermoelectric engine, however, there will, of course, beno plug. Also wire clip structures 162 are preferably provided forsecuring wires within the thermoelectric cassette 108. Additional clipstructures 160 are provided for attaching the outer fan cover 120thereto. As shown in FIG. 11, outer fan cover 120 includes a pluralityof flanges 186 which can be fitted into and engaged with the clips 160so as to secure the outer fan cover to the outer plate 124.Alternatively, fan cover 120 could be attached to outer plate 124 bymeans of suitable mechanical fasteners, such as screws.

Disposed on the inner half of the insulating panel 126 is an inner plate128, an inner heat sink 150, an inner centrifugal fan 146 operativelycoupled with fan motor 132, and an inner fan cover 130 forming a scrollhousing 131 over the inner fan 146 and an air plenum 133 around innerheat sink 150. Details of the construction of the inner plate 128 areshown in FIGS. 12C and 12D. Inner plate 128 includes an opening 172 toaccommodate inner heat sink 150 and a circular embossment 200 foraccommodating the end of the cup 152 formed in insulating panel 126 (seeFIG. 11). Inner plate 128 further includes a plurality of clips 176 intowhich flanges 188 of inner fan cover 130 may be fitted to secure theinner fan cover 130 to the inner plate 128. Fan cover 130 could beattached to inner plate 128 by means of mechanical fasteners, such asscrews. Two raised bosses 148 are provided for receiving screws or otherfasteners for securing the fan motor 132 in place.

Inner plate 128 also preferably includes an air deflector/diffuser 178.When the cassette structure 108 is installed into the cooler/warmerunit, deflector/diffuser 178 extends downwardly into the compartment 62of the main body 22. Therefore, air generated by inner fan 146 andpassing over inner heat sink 150 will be directed by thedeflector/diffuser 178 into the main body compartment 62.

The entire assembly is constructed in a sandwich configuration with theinsulating panel 126 sandwiched between the inner plate 128 and theouter plate 124. Preferably, a plurality of raised bosses 174 areprovided on the upper side of the inner plate 128. When the cassette isassembled, bosses 174 extend into holes 156 formed in insulating panel126. Outer plate 124 preferably has a plurality of holes 168. Thesandwiched structure is held together by screws or other suitablefasteners inserted through holes 168 into raised bosses 174.Alternatively, the sandwiched structure could be held together by othermeans, such as, for example, protuberances, or other protrusions,extending from one plate which engage openings formed in the otherplate.

Outer heat sink 122, inner heat sink 150, thermoelectric module 138,module retaining device 140, and spacer means 144 are preferably heldtogether and in place by two suitable fasteners, such as bolt and nutcombinations, extending from one heat sink into the other. Asalternative to the embodiment shown in FIG. 11, spacer means 144 couldbe an integral part of a heat sink, formed, for example, by machining,casting, extruding, or molding. The fasteners pass through tubularmembers 142 fixed onto opposite sides of the module retaining device140. Accordingly, it can be appreciated that the module retaining device140, module 138, spacer means 144, and the insulating panel 126 aresecurely sandwiched between the outer heat sink 122 and the inner heatsink 150, the spacer means 144 completing a thermal connection betweenthe module 138 and the outer heat sink 122 in a known manner.

It is a further aspect of the present invention to provide animprovement in heat sink construction. As shown in FIG. 13, the outerheat sink 122 of the present invention is in most respects ofconventional design. It includes a flat base portion 194 with aplurality of mutually parallel longitudinally extending fins 192 whichextend perpendicularly from the flat base 194. Unlike conventionalfinned heat sinks, however, heat sink 122 is preferably not rectangular.

As shown in FIG. 13 outer heat sink 122 is disposed in close proximityto outer centrifugal fan 134. When a centrifugal fan is placed in closeproximity to a conventional, rectangular heat sink, as is oftennecessary within the close confines of a portable cooler/warmer unit, oralso, for example, within a personal computer, the velocity distributionof the air generated by the fan and directed by the housing over theheat sink is not uniform across the width of the heat sink because themoving air contacts the fins of the heat sink at different angles.Nonuniform air flow over the heat sink causes inefficient heat transferbetween the moving air and the heat sink because heat transfer at finswhere air is moving at a lower velocity is generally less than at finswhere air is moving at a greater velocity. This is not a problem wherethe fan is spaced from the heat sink by a sufficient distance so thatthe air flow that reaches the heat sink is essentially uniform.

The present inventors have found that by appropriately shaping the endof the heat sink nearest the fan, that is, the intake end, theuniformity of the air velocity distribution across the width of the heatsink is improved. The heat sink 122 of FIG. 13 includes an intake end198 in close proximity to fan 134 and a discharge end 196 furtherremoved from fan 134 than intake end 198. Fan 134 includes a pluralityof backwardly curved blades 190 swept such that clockwise rotation offan 134 in direction ω generates air flow tangentially to and radiallyoutward from fan 134. The scroll portion 121 (shown in phantom in FIG.13) of the cover 120 (also shown in phantom in FIG. 13) captures the airflow and discharges it in a desired direction. In the case of acentrifugal fan rotating clockwise, most of the discharge occurs abovethe axis O of the fan at location D when looking down on the fan and fancover. Of course, for a counterclockwise rotating fan, most of the airwould be discharged below the axis of the fan for the scroll housingconfiguration shown in FIG. 13.

Because most of the discharge occurs at D, the fins located above theaxis O of the fan would capture most of the discharged air flow if theintake end were straight and if the center of the heat sink were alignedwith the center O of the fan. To even the distribution of the air acrossthe heat sink, or at least to achieve maximum air flow through thecenter of the heat sink, assuming the heat source, e.g., thethermoelectric module, is closest to the center of the heat sink, thecenter of the heat sink can be offset with respect to the center O ofthe fan, so that the center of the heat sink is aligned with thedischarge area D. This, however, results in an inefficient use of space.

Alternatively, the present inventors have discovered that the airflowcharacteristics can be improved by shaping the intake end 198, or byturning the orientation of the heat sink with respect to the fan, sothat the fins directly adjacent the discharge area D are further removedfrom the fan than the fins not located proximate the discharge area.Accordingly, compared to a heat sink with a straight, i.e.,perpendicular, intake end, a smaller proportion of the discharged airwill be captured by the fins located adjacent the discharge area D andfins further removed from the discharge area D will capture a largerproportion of the discharged air so that the overall air flowdistribution across the heat sink will be more equalized. Preferably,the proper intake end shaping is accomplished by forming the heat sinkas an oblique parallelogram as shown in FIG. 13.

Intake end 198 is shifted from a line perpendicular to the fins 192 byan angle Θ₁. The magnitude of Θ₁ is determined by the configuration ofthe scroll portion 121 of the housing 120. It is presently preferredthat Θ₁ be 15 degrees. The discharge end 196 need not be speciallyshaped and may be perpendicular to the fins 192, although, for ease ofmanufacturing, it is preferred that discharge end 196 be shifted fromperpendicular by an angle Θ₂, which is preferably equal to Θ₁. Also, asshown in FIG. 13, with fan 134 rotating in a clockwise direction ω suchthat air flow generated by fan 134 is directed radially away from thefan, end 198 is skewed from normal in a clockwise direction by angle Θ₁so that the fins on the upper half of the heat sink are further removedfrom the fan than those on the lower half. On the other hand, if thesweep of the blades of the fan were opposite so that outward radial flowwould be generated by counterclockwise rotation of the fan, end 198would be skewed from normal in a counterclockwise direction by angle Θ₁.

Orienting the discharge end so as to achieve a more equal air flowdistribution across the width of the heat sink may also be accomplishedby skewing a rectangular heat sink so that the distance between theintake end of the heat sink and the fan decreases progressing away fromthe discharge area of the housing. Alternatively, the intake end of thefan may be curved to achieve the same effect.

The above-described phenomena are illustrated in FIGS. 14A-14D. In FIG.14A is shown a rectangular heat sink 210 with a straight perpendicularintake end 216. The fan 200 is disposed within a scroll, or volute,housing 202 having a straight discharge portion D. The airflow isrepresented schematically by arrows A, the larger and bolder the arrowthe greater the relative volume of airflow. As can be appreciated fromFIG. 14A, the greatest volume of discharged air is captured by the topportion of heat sink 210, while the bottom portion of the heat sinkcaptures little or no discharged air.

In FIG. 14B is shown a rectangular heat sink 210 with a straightperpendicular intake end 216. The fan 200 is disposed within a scroll,or volute, housing 206 having a somewhat more restricted, inwardlyangled discharge portion D. As can be appreciated from FIG. 14B, theinward angling of the discharge of the housing 206 does direct some ofthe discharged air away from the top fins so that, in general, theremaining fins capture a greater volume of the discharged air than withthe housing configuration of FIG. 14A.

In FIG. 14C is shown a heat sink 212 with a straight, but angled intakeend 214. The fan 200 is again disposed within a scroll housing 206having a somewhat more restricted, inwardly angled discharge portion D.As can be appreciated from FIG. 14C, the angling of intake end 214results in an even greater volume of discharged air being captured bythe lower fins of heat sink 212. This is because the greater distancebetween the discharge D and the upper fins permits the discharged air inthe area of the upper fins to expand more and thus become more evenlydistributed.

Finally, in FIG. 14D is shown a heat sink 218 with a curved intake end220. The fan 200 is again disposed within a scroll housing 206 having asomewhat more restricted, inwardly angled discharge portion D. As can beappreciated from FIG. 14D, the curve of intake end 214 results in aneven greater volume of discharged air being captured by the lower finsof heat sink 218. This is because, as with the angled intake end 214shown in FIG. 14C, the greater distance between the discharge D and theupper fins permits the discharged air in the area of the upper fins toexpand more and thus become more evenly distributed.

It will be realized that the foregoing preferred specific embodiments ofthe present invention have been shown and described for the purposes ofillustrating the functional and instructional principles of thisinvention and are subject to change without departure from suchprinciples. Therefore, this invention includes all modificationsencompassed within the spirit and scope of the following claims.

What is claimed is:
 1. A container comprising:a main body having a basewall and four sidewalls extending from said base wall so as to define aproduct receiving compartment; a lid member constructed and arranged tobe movable with respect to said main body between (1) a closed positionclosing off said product receiving compartment and (2) an openedposition permitting access to said product receiving compartment; and atray member constructed and arranged to be movable with respect to saidmain body and said lid member between (1) a stowed position whereby saidtray member is engaged with and movable with said lid member betweensaid closed position and said opened position and (2) a deployedposition wherein said tray member is engaged with said main body topresent a generally upwardly facing supporting surface and said lidmember is movable between said opened position and said closed positionindependently of said tray member.
 2. A container comprising:a main bodyhaving a base wall and four sidewalls extending from said base wall anddefining a product receiving compartment; a lid member constructed andarranged to be movable between (1) a closed position closing off saidproduct receiving compartment and (2) an opened position permittingaccess to said product receiving compartment, said lid member includingfirst engagement structure; and a tray member comprising: a firstsupporting surface, having a raised portion extending proximate aperipheral edge thereof to inhibit products supported on said firstsupporting surface from sliding off said peripheral edge thereof; asecond supporting surface opposite said first supporting surface, saidsecond supporting surface having a raised portion extending proximate aperipheral edge thereof to inhibit products supported on said secondsupporting surface from sliding off said peripheral edge thereof; andsecond engagement structure complimentary to said first engagementstructure of said lid member, wherein engagement of said firstengagement structure with said second engagement structure detachablysecures said tray member to said lid member so as to present a one ofsaid first and second supporting surfaces.
 3. The container of claim 2wherein said tray member further includes first pivoting connectingstructure and said main body further includes second pivoting connectingstructure corresponding to said first pivoting connecting structure ofsaid tray member, said first pivoting connecting structure of said traymember being constructed and arranged to be detachably engagable withsaid second pivoting connecting structure of said main body so as topermit said tray member to pivot with respect to said main body and withrespect to said lid member to a deployed position in which the other ofsaid first and second supporting surfaces is presented when said firstpivoting connecting structure is engaged with said second pivotingconnecting structure.
 4. The container of claim 1, further comprising:anelectrically powered temperature maintaining apparatus constructed andarranged to selectively warm or cool said product receiving compartment,said electrically powered temperature maintaining apparatus including apower cord for connecting said electrically powered temperaturemaintaining apparatus to an electric power source; and a handle membercoupled with at least one of said main body and said lid member andconstructed and arranged to permit said container to be carried by saidhandle member, said handle member including cord stowing structure fixedthereto and constructed and arranged to permit said power cord to bewrapped therearound and to support said wrapped power cord thereon. 5.The container of claim 1, further comprising:a handle member having twoleg portions and a transverse portion extending between respective firstends of said leg portions, said handle member being coupled atrespective second ends of said two leg portions with two of saidsidewalls of said main body so as to be movable between (1) an operativeposition that permits said container to be carried by said handle memberand (2) a stowed position; and lid clearance structure associated withsaid one sidewall of said main body, said lid clearance structureconstructed and arranged to provide a clearance between an edge of saidlid member and a surface on which said container is supported when saidcontainer is resting on said surface on said one sidewall to permit saidlid member to move freely between said opened position and said closedposition in said generally lateral direction without said edge of saidlid member scraping said surface on which said container is supported,said lid clearance structure including at least one raised rib formed onan outer surface of said one sidewall.
 6. The container of claim 5wherein said transverse portion of said handle member is disposed alongan outer surface of said one sidewall when said handle member is in saidstowed position and wherein said lid clearance structure includes saidtransverse portion of said handle member disposed along said outersurface of said one sidewall.
 7. The container of claim 1 wherein:saidbase wall, said four sidewalls, and said lid member disposed in saidclosed position define a width, a length, and a height of saidcontainer, an aspect ratio of said height to said length and an aspectratio of said height to said width being less than 1 to permit saidcontainer to sit in a stable position on the automobile seat and topermit said container to be used on the automobile seat withoutobstructing movement or vision of occupants of the automobile.
 8. Thecontainer of claim 1, further comprising:a thermoelectric engineconstructed and arranged to selectively cool or warm said productreceiving compartment mounted to said main body adjacent top edges ofthree of said four sidewalls, said thermoelectric engine constructed andarranged to permit said thermoelectric engine unit to be attached to andremoved from said main body as an integral modular unit to facilitateassembly or repair of said thermoelectric engine.
 9. The container ofclaim 8, said thermoelectric engine comprising:component mountingstructure constructed and arranged to permit a plurality of componentsof said thermoelectric engine to be mounted thereon; a first fan; afirst heat sink disposed adjacent said first fan; a first fan covermounted to said component mounting structure and defining a housingaround said first fan and a plenum around said first heat sink, saidfirst fan, said first heat sink, and said first fan cover being disposedon a first half of said thermoelectric engine unit; a second fan; asecond heat sink disposed adjacent said second fan; a second fan covermounted to said component mounting structure defining a housing aroundsaid second fan and a plenum around said second heat sink, said secondfan, said second heat sink, and said second fan cover being disposed ona second half of said thermoelectric engine unit opposite said firsthalf; a fan motor mounted to said component mounting structure andoperatively coupled with said first and second fans; and athermoelectric module disposed between and in thermal contact with saidfirst and second heat sinks.
 10. The container of claim 9, wherein atleast one of said first and second heat sinks comprises:a flat base; anda plurality of mutually parallel longitudinal fins extending from saidflat base, each of said plurality of longitudinal fins having an intakeend disposed proximate the respective fan and a discharge end furtherremoved from the respective fan compared to said intake end, whereinrespective intake ends of substantially all of said plurality oflongitudinal fins are disposed along a first transverse end line andwherein said first transverse end line is generally non-perpendicularwith respect to said plurality of longitudinal fins.
 11. The containerof claim 10 wherein said first transverse end line is straight and isdisposed at an oblique angle with respect to said plurality oflongitudinal fins.
 12. The container of claim 10 wherein said firsttransverse end line is curved.
 13. The container of claim 1 wherein saidlid member defines a generally planar structure and said tray memberdefines a generally planar structure, said lid member and said traymember being disposed in a side-by-side, generally parallel orientationwhen said tray member is in said stowed position so that said lid memberand said tray member together define a generally planar door assembly.14. The container of claim 1 wherein said lid member is pivotallyconnected to said main body so as to be pivotable with respect to saidmain body about a lid pivot axis and said tray member is pivotallyconnected to said main body so as to be pivotable with respect to saidmain body about a tray pivot axis.
 15. The container of claim 14 whereinsaid lid pivot axis is spaced from and generally parallel to said traypivot axis.
 16. The container of claim 1 wherein said tray member isconstructed and arranged to be removable from both said main body andsaid lid member.
 17. The container of claim 2 wherein said tray memberis constructed and arranged to be movable between (1) a stowed positionwherein said tray member is detachably secured to and movable with saidlid member between said closed position and said opened position and (2)a deployed position wherein said tray member is engaged with said mainbody to present the other of said first and second supporting surfacesand said lid member is movable between said opened position and saidclosed position independently of said tray member.
 18. The container ofclaim 4 wherein said handle member includes an elongated portion andsaid cord stowing structure comprises two longitudinally spacedtransverse rib members extending from said elongated portion of saidhandle member and a longitudinal portion attached to distal ends of saidtransverse rib members and extending generally longitudinally withrespect to said elongated portion, said two transverse rib memberproviding structure for wrapping the cord therearound between saidelongated portion of said handle member and said longitudinal portion ofsaid stowing structure.
 19. The container of claim 4, said handle memberhaving two leg portions and a transverse portion extending betweenrespective first ends of said two leg portions, said handle member beingcoupled at respective second ends of said two leg portions with two ofsaid four sidewalls of said main body so as to be movable between (1) anoperative position that permits said container to be carried by saidhandle member and (2) a stowed position, and said cord stowing structurecomprising two transverse rib members extending from and spacedlongitudinally with respect to one of said two leg portions of saidhandle member and a longitudinal portion attached to distal ends of saidtransverse rib members and extending generally longitudinally withrespect to said one leg portion, said two transverse rib memberproviding structure for wrapping the cord therearound between said oneleg portion of said handle member and said longitudinal portion of saidstowing structure.
 20. The container of claim 5 wherein said lidclearance structure includes one or more raised ribs provided on saidone sidewall.
 21. The container of claim 5 wherein said one side wallhas an elongated recess formed along an outer edge thereof opposite saidbase wall and said end walls have elongate recesses formed along outeredges thereof opposite said base wall and extending from said elongatedrecess formed on said one side wall generally to a location at whichsaid respective second ends of said two leg portions of said handlemember are coupled with said end walls, said elongated recesses formedon said one side wall and said end walls defining a handle stowingrecess in which said handle member is stowed when in said stowedposition.
 22. The heat sink of claim 9 wherein said oblique angle is 15degrees.
 23. The heat sink of claim 8 wherein said respective dischargeends of substantially all of said plurality of longitudinal fins aredisposed along a second transverse end line and wherein said secondtransverse end line is generally non-perpendicular with respect to saidplurality of longitudinal fins.
 24. The heat sink of claim 23 whereinsaid first transverse end line and said second transverse end line arestraight lines oriented in a generally parallel relationship and aredisposed at an oblique angle with respect to said plurality oflongitudinal fins.